Door closers having a cylinder with a spring biased arm or rod have been known for many years for use on screen doors and storm doors. The closer normally biases the door to a closed position so that the door will automatically shut after being opened. Various mechanisms have been provided on door closers so as to hold the door in an open position.
One example of a door closer with a mechanism for holding the door open is disclosed in U.S. Pat. No. 5,832,562. This closer uses a cylinder with a spring biased rod extending through a washer in the cylinder. A button on the cylinder moves the washer to a canted position relative to the rod so as to frictionally retain the rod in an extended position so as to hold the door open. This structure relies solely upon the friction between canted washer and the rod to hold the door open. Thus, wind forces on the outside of the door may overcome the friction so as to wholly or partially close the door.
Another example of a closer with a mechanism to retain the door in an open position is disclosed in U.S. Pat. No. 4,639,969, which utilizes a plurality of notches in the rod and a pawl which engages one of the notches to maintain the door in an open position. A problem with this mechanism is that the pawl must be manually lifted from engagement with the rod so as to allow the door to close.
Therefore, a primary objective of the present invention is the provision of an improved door closer with a mechanism to retain the door in an open position.
Another objective of the present invention is the provision of a door closer having a mechanical lock to hold the door in a selected one of multiple open positions.
A further objective of the present invention is the provision of a door closer having a button-actuated mechanism to retain the door in an opened position.
Another objective of the present invention is the provision of a door closer having a mechanism to hold the door in an open position which can be de-actuated quickly and easily.
Yet another objective of the present invention is the provision of an improved door closer having a mechanism to retain the door in an open position, with the mechanism being released simply by opening the door slightly further, so that the door will close.
A further objective of the present invention is the provision of an improved door closer having a mechanism to retain the door in a selected open position and which is economical to manufacture and durable and safe in use.
These and other objectives will become apparent from the following description of the invention.